INVESTIGATING TOXICOLOGY OF THIOL-CAPPED QUANTUM DOTS OF CADMIUM AND LEAD

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 研究了硫醇修饰的CdSe、CdS、PbSe和PbS量子点在体内的毒理学和药代动力学。工作的重点是开发分析和仪器方法，以合成稳定的硫醇包裹的CdSe纳米颗粒及其表征。我们采用了两种不同的方法来制备CdSe纳米颗粒，因为我们使用了硫代甘油或巯基乙酸来稳定纳米颗粒。在任何一种情况下，硫醇包裹的CdSe纳米颗粒在环境条件下都可以高度稳定数月。提纯研究也已完成。用紫外-可见光谱和透射电子显微镜对其进行了表征。数据表明，通过改变增粘剂或硒的用量，可以在2-4 nm之间改变尺寸。在不同的溶剂中进行了超声稳定性试验。在超声波作用下，颗粒在水中高度稳定，但在乙醇和酸性介质中表现出不稳定，从而导致聚集。考察了介质对从动物组织中提取离子Cd的影响，以及动物器官中离子Cd和Cd Se的形态分布。水和乙醇不适合从生物组织中提取Cd。然而，在酸性介质中实现了萃取，但酸的使用导致了CdSe纳米颗粒的分解，从而在溶液中引入了额外的离子Cd。四甲基氢氧化铵(TMAH)适合作为萃取剂。用肝标准物质(DORT-4)测定时，萃取率在85-100%之间。CdSe纳米颗粒的处理不会导致Cd从纳米颗粒到溶液的超声降解，也不会在TMAH消化过程中引起任何降解。未经处理的和处理过的CdSe NP溶液的CD信号差异在统计学上是不显著的。报告了初步数据，以深入了解Cd和CdSe NPs在器官中的分布。数据表明，在器官(肝脏和肾脏)中，大部分镉以离子镉的形式存在。NPs暴露在光下可引起离子镉水平的增加。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Research is performed to elucidate toxicology and pharmacokinetics of thiol-capped CdSe, CdS, PbSe and PbS quantum dots (QDs) in vivo. Efforts have focused on the development of analytical and instrumental methods for as well synthesis of stable thiol-capped CdSe nanoparticles and their characterization. Two different routes were utilized for producing CdSe NPs in that we either used thioglycerol or mercaptoacetic acid for stabilizing the NPs. In either scenario, thiol-capped CdSe NPs were highly stable for months under ambient conditions. Purification studies were also completed. Characterization was performed with UV-visible spectrometry and TEM. Data indicated that size could be varied from 2-4 nm by varying the amount of accping agent or selenium. Stability tests were under sonication in different solvents. Particles were highly stable in water under ultrasounds, but exhibited instability in alcohol and acidic media resulting aggregation. Effect of the media was examined on the extraction of ionic Cd from animal tissues for speciation of ionic Cd and CdSe from the animal organs. Water and ethanol were unsuitable for extraction of Cd from biological tissues. Extraction achieved in acid media, however, the use of acid resulted in decomposition of CdSe NPs that introduced additional ionic Cd to solution. Tetramethylammonium hydroxide (TMAH) was found to be suitable for extraction. Extraction efficiency was ranged between 85-100% when testetd with liver reference material (DOLT-4). Treatment of CdSe NPs did not induce and degradation of Cd from NPs to solution ultrasounds, nor did cause any degradation during TMAH digestions. The differences in Cd signals from untreated and treated CdSe NP solutions were statistically insignificant. Preliminary data is reported to get an insight into the distribution of Cd and CdSe NPs in organs. Data indicated that majority of CdSe is in the form of ionic Cd in the organs (liver and kidney). Exposure of NPs to light induces enhancement on the levels of ionic Cd.